This invention relates to feed systems for work tools, and in particular, to a feed system for a band saw. While the feed mechanism is described with particular reference to its band saw application, those skilled in the art will recognize the wider applicability of the inventive principles disclosed hereinafter.
A number of automatic feed arrangements are known in the prior art. In general, these prior art devices operate to incrementally advance a work piece past a work station where operations may be conducted on the work piece. In the case of a band saw, large length pieces are advanced through a cutting station, where they are cut into smaller incremental parts for later use in a construction process.
As indicated, feeds of various kinds have been known for a long time. Automatic feeds are employed extensively in punch press operations, for example. In such an operation, some form of shuttle vise is provided to advance the work piece incrementally across an operating position where an operation is conducted on the work piece. This same arrangement has been employed in feeds for other devices. For example, the U.S. Pat. to Harris, No. 3,504,585 adopts this form of feed arrangement to a band saw.
While these prior art arrangements have worked for their intended purposes, as a class they exhibit relatively high initial cost, are not readily adaptable in the field to a particular machine, and are not capable of standardization in construction so as to facilitate their use for a variety of feed or associated equipment sizes because of various deficiencies in their design.
The invention disclosed hereinafter overcomes these prior art difficulties by providing a feed unit which is compatible with a wide variety of machine tools. The unit as designed is intended to be field attachable. That is to say, the feed can be attached to a band saw, for example, without requiring the removal of the band saw from its field installation. Feed attachment itself can be accomplished with simple tools. The control system employed for controlling feed operation can be adapted to a wide range of feed mechanisms. In the embodiment discussed hereinafter, the control system is employed in conjunction with a fluid system, preferably pneumatic, although an electrically operated control can be employed if desired. In the fluid control system of the present invention, a centrally located processor is utilized to receive signal inputs from a plurality of sensors, and to provide fluid control signals to various operating devices to control feed operation. These fluid control signals, in the embodiment illustrated, operate directly on various drive cylinders of the feed mechanism. With larger feed mechanism designs, the same control system can be employed to provide pilot signals to control the operation of larger hydraulic, pneumatic or other types of fluid devices.
There are a number of particular areas which distinguish the feed mechanism of my invention over other prior art designs in addition to the control system mentioned above. The feed mechanism of this invention employs a simplified adjustment system providing both coarse and fine adjustments for feed set up, so that an operator can incrementally and precisely adjust the incremental length of cut of a band saw, for example. In addition, the invention disclosed hereinafter employs an improved shuttle vise design that ensures accurate stroke direction while permitting the accommodation of irregular stock material work pieces. Because of the structural features disclosed hereinafter, I can produce a feed mechanism having a greater variety of features, and produce it at a lower cost than those previously available and disclosed in the prior art.
One of the objects of this invention is to provide an improved feed system for a work tool.
Another object of this invention is to provide a feed system for a work tool employing a control mechanism which may be utilized over a wide range of feed system sizes.
Another object of this invention is to provide a feed system having an adjustment scheme providing both a quick coarse position adjustment and a fine adjustment for regulating the feed length of a shuttle vise.
Another object of this invention is to provide a feed system which is adaptable for use with a variety of machine tools and may be readily connected to those tools.
Another object of this invention is to provide an indexing mechanism which automatically compensates for warpage and other nonuniform characteristics of a work piece.
Yet another object of this invention is to provide an indexing mechanism which ensures straight line operation of a drive mechanism for a shuttle vise but permits the vise to float to accommodate warpage in the work piece.
Other objects will be apparent to those skilled in the art in light of the following description and accompanying drawings.